Resonant cavity wave fluid compressor

ABSTRACT

The invention comprises a wave fluid compressor which consists essentially of a resonant cavity or whistle. As fluid flows within the cavity, pressure waves of high and low pressure are created. Specifically, when a high pressure compression wave is stopped at the closed end of the resonant cavity and then reversed the pressure doubles as the kinetic energy of the wave is converted into potential energy of pressure. When a high pressure compression wave exits from the cavity, it is followed by a rarefaction wave which flows to the closed end of the tube, reverses, and returns to be followed by another high pressure compression wave. In combination with the resonant cavity the invention further comprises check valves at the closed ends of the tube so that a portion of the high pressure may be withdrawn from one check valve, and a portion of the low pressure may be withdrawn through another check valve so as to provide an amplified differential pressure. The invention also comprises a taper within the resonant cavity such that the differential pressure is further increased thereby. The differential pressure extracted from the resonant chamber is utilized to move a mechanical load such as for moving a mechanical piston or the like.

United States Patent [191 Warren Get. 16, 1973 RESONANT CAVITY WAVE FLUID COMPRESSOR [75] Inventor: Raymond W. Warren, McLean, Va.

[73] Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC.

[22] Filed: July 26, 1972 [2i] Appl. No; 275,376

[52] US. Cl 60/412, 417/151, 137/624.l4

[51] Int. Cl. FlSb 15/18 [58] Field of Search 417/151; 60/370,

[5 7] ABSTRACT The invention comprises a wave fluid compressor which consists essentially of a resonant cavity or whistle. As fluid flows within the cavity, pressure waves of high and low pressure are created. Specifically, when a high pressure compression wave is stopped at the closed end of the resonant cavity and then reversed the pressure doubles as the kinetic energy of the wave is converted into potential energy of pressure. When a high pressure compression wave exits from the cavity, it is followed by a rarefaction wave which flows to the closed end of the tube, reverses, and returns to be followed by another high pressure compression wave. In combination with the resonant cavity the invention further comprises check valves at the closed ends of the tube so that a portion of the high pressure may be [56] References Cited withdrawn'from one check valve, and a portion of the UNH'ED STATES PATENTS low pressure may be withdrawn through another 685 704 10/1901 Wilkinson 60,412 X check valve so as to provide an amplified differential 2 674'09l M1954 Malicknm: ":::"i pressure. The invention also comprises a taper Within 2Z780I066 2/1957 Tarry 60/370 he resonant cavity such that the differential pressure 3,058,310 10/1962 P nissi i 60/370 is further increased thereby. The differential pressure 3,234,934 2/1966 Woodward 60/370 extracted from the resonant chamber is utilized to move a mechanical load such as for moving a mechan- Primary Examiner-Edgar W. Geoghegan ical piston or the like. Attorney-Harry M. Saragovitz et al.

10 Claims, 2 Drawing Figures fi 14 i E 1 LOAD resonance.

RESONANT CAVITY WAVE FLUID COMPRESSOR RIGHTS OF THE GOVERNMENT The invention described herein may be manufactured, used, andlicensed by or for the United States Government for governmental purposes without the payment to the inventor of any royalty thereon.

BACKGROUND'OF THE INVENTION This invention relates generally to fluid handling'devices and, more particularly, to a fluid pressure amplifier which utilizes compressed air and rarefied air obtained through check valves in order to create a differential pressure. 7

The broad concept of creating a differential pressure from a fluidic means contemplated the use of a fluidic oscillator. This fluidic oscillator was used to drive a piston by utilizing a differential pressure therefrom as is evidenced by the Woodward U.S. Pat. No. 3,234,934.

While the Woodward disclosure has anticipated the broad concept of utilizing-the differential pressure from an oscillator to move a piston it does not contemplate a method for creating a differential pressure utilizing A more complex device utilizing a differential pressure obtained from a resonant chamber has been evidenced by the U.S. Pat. No. 3,556,120 to P. Bauer. This device, however, utilizes a pure fluid oscillator in combination with a resonant chamber tube terminated by a piston. In this particular device the pressure differential effected by the resonant chamber tube acts upon the power stream issuing from a fluidic oscillator to alternately switch the power stream to two output channels.

Heretofore pressure fluid amplifiers have depended upon the deflection of a power fluid stream by side control jetsin order to guide the flow direction of the power stream to the receiver in order to create a pressure differential. Other types of fluid amplifiers have used the controlled flow to induce rotation in the power stream and therefore generate a vortex with a resultant high pressure drop from theouter circumference of the vortex chamber into'the fluid outlet.

It is therefore an object of this invention to utilize wave resonance effects from a flow to compress a portion of the flow to ahigher air pressure than would be obtained from the wave effect alone.

It is therefore another object of this invention to provide a new and novel device which utilizes the rarefaction of fluid in a resonant chamber to compress fluid to a higher pressure.

Another object of the present invention is to provide a wave fluid compressor in which the resonant cavity by virtue of its geometric configuration and tapering furnishes additional compression of the fluid waves therein.

These and other objects of present invention will become more fully apparent with reference to the following specification and drawings which relate to a preferred embodiment of the invention described herein.

SUMMARY OF THE INVENTION The wave fluid compressor of the present invention utilizes a resonant fluid cavity or in the alternative, a whistle to create waves of higherand lower pressure. Inside the resonant cavity periodically a high pressure compression wave is stopped at the closed end of the cavity and reversed in direction. This reversal causes a pressure to double because kinetic energy of the wave is converted into potential energy of pressure. Upon the issuance of a high pressure compression wave from the cavity a rarefied compression wave is created which flows to the closed end of the cavity. A high pressure check valve at the closed end of the cavity withdraws a portion of high pressure fluid. A low pressure valve located nearby the closed end of the cavity withdraws a portion of the low pressure fluid. The high pressure and low pressure fluids are then utilized to create a differential pressure on opposite faces of a piston located within a chamber and connected to a mechanical load such that said differential pressure causes the piston to move and therefore move the mechanical load. Alternatively, the'high pressure fluid portion withdrawn is stored in a fluidic capacitor.

BRIEF DESCRIPTION OF THE DRAWINGS The above .and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, especially when taken in conjunction with the accompanying drawings in which:

FIG. 1a is a cross section of the wave fluid compressor showing the resonant cavity, piston chamber and mechanical load.

FIG. lb is a direct view of the entrance to the resonance cavity of the wave fluid compressor.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the FIG. la of the accompanying drawings, there is illustrated a pure fluid resonant cavity 24 arranged such that fluid entering the entrance 19 of said cavity 24 creates high pressure waves and low pressure waves within the space 20. The resonant chamber 24 utilizing only the flow of fluid from a pilot pressure source at the entrance l9 presses said fluid to a pressure higher than that of the entrance pressure. As fluid flows within the space 20, pressure waves of high and low pressures are created. Specifically, when a high pressure compression wave is stopped at the closed end 34 of the resonant cavity 24 and then reversed, the pressure doubles as the kinetic energy of the wave is converted into potential energy of pressure at the closed end 34. Moreover, when a high pressure compression wave exits from the cavity at the entrance 19, it is followed by a rarefaction wave which flows to the closed end 34 of the cavity space 20, reverses, and returns to be followed by another high pressure compression wave.

Note, a fluid power source, not illustrated, is directed into the entrance 19 of the resonant cavity 24 and supplies pressurized fluid thereto.

At the closed end 34 of the resonant cavity 24 is located a high pressure check valve 30 through which a portion of the high pressure fluid within the space 20 is withdrawn. Near the closed end 34 is located a low pressure check valve 40 through which a portion of the low pressure fluid in the space 20 is withdrawn and permitted to enter through the conduit 42 and the conduit 41 into the closed chamber 15 terminated by piston 10. The high pressure fluid accumulated at the space 31 is permitted to pass through the passageway 32 and through the conduit 33 into the chamber space 16 terminated by the rear of piston 10.

The amount of fluid withdrawn through each valve is directly dependent upon the resonant frequency of the cavity 24. Both high pressure valve 30 and low pressure valve 40 are operated once each cycle of oscillation of the fluid within the space 20. Only a small amount of fluid flow is removed during each cycle of the resonant cavity 24. This procedure is followed to prevent the resonant cavity 24 from terminating its oscillation. However, resonant cavities such as resonant cavity 24 operate easily in the frequency range, 500 Hz to 2,000 Hz, and pumping therefore is very rapid.

The walls 35 of the resonant cavity 24 which define the space 20 are tapered away from the entrance 19. This tapering allows the pressure within the space 20 to be further amplified by introduction of the fluid waves into a smaller and smaller cavity section. The tapered wall 35 raises the pressure of the compression wave above that of a conventional resonant cavity having parallel walls. The tapered walls 35 have a compressional effect as the fluid wave approaches the small end 34. Conversely, the rarefaction wave is further reduced in pressure at the small end 34 of the space 20. Hence additional compressional advantage is provided by the taper 35. Referring to the chamber 12 in FIG. 1a note that as the high pressure fluid builds up within the chamber space 16 and a lower pressure builds up within the chamber space 15 a differential pressure is created at the exposed faces of the piston which causes the piston 10 to move in the direction of the lower differential pressure or toward the space and away from the high pressure space 16. This movement of the piston 10 causes the load 18 attached thereto to acquire kinetic energy by means of the connecting member 11 interconnecting the piston 10 to the load 18 and extending through an aperture 14 in the chamber wall.

Referring now to FIG. lb of the accompanying drawings, there is illustrated the entrance 19 of FlG. la. FlG. lb shows that the entranceway 19 to the resonant cavity 24 is bifurcated and comprises equiformal entrances 22 and 23 separated by member 21.

While one specific embodiment of the invention has been described and illustrated, it will be clear that variation of the details of construction which are specifically illustrated and described may be resorted to by persons skilled in this art without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

l. A wave fluid compressor comprising:

first means for receiving said fluid;

second means connected to said first means for providing fluid having a high pressure and fluid having low pressure;

third means connected to said second means for withdrawing a portion of said fluid having a high pressure;

fourth means connected to said second means for withdrawing a portion of said fluid having a low pressure.

2. The wave fluid compressor of claim 1 wherein said second means comprises a resonant cavity having inside walls.

3. The wave fluid compressor of claim 2 wherein said first means comprises a slit in said cavity.

4. The wave fluid compressor of claim 3 wherein said third means comprises a high pressure check valve and wherein said fourth means comprises a low pressure check valve.

5. The wave fluid compressor of claim 4 further comprising a fifth means for compressing said fluid, said means being a part of said cavity.

6. The wave fluid compressor of claim 5 wherein said fifth means comprises a taper of the inside walls of said resonant cavity away from said slit.

7. The wave fluid compressor of claim 6 wherein the walls of said cavity form a conical space.

8. The wave fluid compressor of claim 7 further comprising means for using said withdrawn fluids to provide mechanical motion.

9. The wave fluid compressor of claim 8 wherein said means for using said withdrawn fluids comprises a chamber having a first port connected to said low pressure check valve and a second part connected to said high pressure check valve, and at least one piston located inside said chamber.

10. The wave fluid compressor of claim 9 further comprising a mechanical load and means for interconnecting said piston to said load. 

1. A wave fluid compressor comprising: first means for receiving said fluid; second means connected to said first means for providing fluid having a high pressure and fluid having low pressure; third means connected to said second means for withdrawing a portion of said fluid having a high pressure; fourth means connected to said second means for withdrawing a portion of said fluid having a low pressure.
 2. The wave fluid compressor of claim 1 wherein said second means comprises a resonant cavity having inside walls.
 3. The wave fluid compressor of claim 2 wherein said first means comprises a slit in said cavity.
 4. The wave fluid compressor of claim 3 wherein said third means comprises a high pressure check valve and wherein said fourth means comprises a low pressure check valve.
 5. The wave fluid compressor of claim 4 further comprising a fifth means for compressing said fluid, said means being a part of said cavity.
 6. The wave fluid compressor of claim 5 wherein said fifth means comprises a taper of the inside walls of said resonant cavity away frOm said slit.
 7. The wave fluid compressor of claim 6 wherein the walls of said cavity form a conical space.
 8. The wave fluid compressor of claim 7 further comprising means for using said withdrawn fluids to provide mechanical motion.
 9. The wave fluid compressor of claim 8 wherein said means for using said withdrawn fluids comprises a chamber having a first port connected to said low pressure check valve and a second port connected to said high pressure check valve, and at least one piston located inside said chamber.
 10. The wave fluid compressor of claim 9 further comprising a mechanical load and means for interconnecting said piston to said load. 